Singapore Corporate Tax Filing Deadline 2026: Form C-S, C-S (Lite), and What Foreign Directors Must File by 30 November

The Singapore corporate tax filing deadline for 2026 is 30 November 2026. By that date, every Singapore company has to file its Year of Assessment (YA) 2026 Corporate Income Tax Return on myTax Portal, unless IRAS has formally waived the filing. That covers companies that made a loss, companies that barely traded, and most companies incorporated in 2025.

If you are a foreign founder running a Singapore Pte Ltd from Dubai, London or Sydney, this is the date that catches people out. The company may have a local nominee director and an accountant, but IRAS is clear that directors stay responsible for filing on time and accurately, even when a tax agent has been engaged. You cannot hand the liability to someone else.

This guide explains which form your company files, what you need set up before you can file from overseas, what happens if you miss the date, and what changed at ACRA on 20 October 2026.

The deadline is 30 November 2026 for all YA 2026 Corporate Income Tax Returns. Singapore taxes companies on a preceding-year basis, so YA 2026 covers the financial year that ended in 2025. If your company’s financial year ended on 31 December 2025, 31 March 2025 or 30 June 2025, the return for that year is due by the same date.

IRAS says more than 323,000 companies need to file this season, including over 37,000 newly incorporated companies. In YA 2025, more than 90% filed on time. IRAS has been firm with the rest, as the penalties section below shows.

There are actually two corporate tax filings each year, and they are often confused:

You can skip ECI only if your revenue is S$5 million or below and your ECI is nil. IRAS measures “nil” before the start-up or partial tax exemption is deducted, so a small profit that will end up fully exempt is still not nil.

Most small foreign-owned companies qualify for a simplified form. IRAS sets the conditions as follows.

Form C-S is available if your company:

• is incorporated in Singapore;
• has annual revenue of S$5 million or below;
• has only income taxable at the 17% corporate rate; and
• is not claiming carry-back of current year capital allowances or losses, group relief, investment allowance, or foreign tax credit and tax deducted at source.

Form C-S (Lite) is for companies that qualify for Form C-S and have annual revenue of S$200,000 or below. It needs only six essential fields. IRAS says about 8 in 10 eligible companies used it in YA 2025.

Form for Dormant Company is for companies that did not carry on business and had no income in the financial year. It needs two declarations.

Form C is for everyone else. Financial statements, tax computations and supporting schedules must be filed with it. A Singapore branch of a foreign company, for example, cannot use Form C-S because it is not incorporated in Singapore.

A common error on Form C-S (Lite) is the field called “Adjusted Profit/Loss before Capital Allowances”. IRAS warns that this is your profit or loss after tax adjustments, not the amount of the adjustments themselves. If you made no adjustments, it should match your net profit or loss before tax.

Usually, yes. IRAS gives these rules for YA 2026:

• Incorporated in 2025: you must file if the company closed its first set of financial statements in 2025 and either earned income or started business in 2025. You do not file yet if the first accounts did not close in 2025, or if they closed but the company had not started business or received income.
• Loss for 2025: you must file if you carried on business or received income during the year.
• Dormant: check “Update Corporate Profile” on myTax Portal. If the status shows “No Business Done”, a waiver has already been granted and no return is needed. If it shows “Active”, file the Form for Dormant Company.

IRAS has also added a Filing Obligations Checker for new companies to its chatbot this year. If you incorporated your Singapore company recently and are not sure where you stand, use it before you assume nothing is due.

The filing itself takes minutes. Getting access is what takes days, so start now if you have never logged in.

Step 1: Sort out Corppass

Returns are filed on myTax Portal through Corppass. The person filing, whether an employee or your tax agent, must have Corppass authorisation as an “Approver” for the “Corporate Tax (Filing and Application)” digital service.

If you are a director without an NRIC or FIN, you can still have a Corppass account. Your company’s Corppass Admin creates the account using your foreign ID, and you then receive a Singpass Foreign user Account to log in with the Singpass app. Allow time for this, and do not leave it to the last week of November.

Step 2: Get your accounts closed and reviewed

You need financial statements and a tax computation. IRAS’s Basic Corporate Income Tax Calculator and the new Business Expense Deductibility Checker can help with the second part. If your revenue is S$200,000 or below, the new Record Keeping Assistant spreadsheet helps organise records for Form C-S (Lite).

Step 3: Choose the form and file

Check the conditions above, pick the form and file. Form C-S filers can also use #SeamlessFilingFromSoftware, which files directly from supported accounting software.

Step 4: Watch for the Notice of Assessment

IRAS processes returns in batches. You pay within one month of the Notice of Assessment, even if you object. Revisions and objections must be made within two months of the notice, and from 1 July 2027 IRAS plans to require all companies to use the digital Revise/Object service.

IRAS’s position for YA 2026 is direct:

• Companies that do not file by the due date can be fined up to S$5,000.
• Continued non-compliance can bring additional daily penalties of S$100.
• Companies that repeatedly fail to file for two years or more face progressively stronger action, and may be ordered by the courts to pay a penalty of twice the tax assessed, on top of the fine.

IRAS also says that since January 2026 it has issued more than 4,100 Notices to Attend Court to companies that failed to file returns for YA 2025 and earlier, collecting more than S$2 million in penalties. If you missed ECI, IRAS may also issue an estimated Notice of Assessment, and you have two months to object to it.

For a foreign director, there is a practical problem too. Court notices and letters go to the registered address. If your corporate secretary is slow to forward mail, you may find out late.

The headline rate is 17%, but very few small companies pay that on every dollar. Three reliefs matter:

• Start-up tax exemption: for a qualifying new company’s first three YAs, 75% of the first S$100,000 of normal chargeable income and 50% of the next S$100,000 are exempt. Investment holding and property development companies do not qualify. We cover the conditions in our post on Singapore start-up exemptions.
• Partial tax exemption: for other companies, 75% of the first S$10,000 and 50% of the next S$190,000 are exempt.
• YA 2026 CIT Rebate: IRAS raised it to 50% of tax payable for YA 2026. Companies that made CPF contributions for at least one local employee in 2025 (excluding shareholder-directors) also get a S$2,000 Cash Grant. Total benefits are capped at S$40,000. You do not claim the rebate on the form; IRAS computes it.

If your company has no local employee, you will not get the Cash Grant. That is common for founder-only companies run from abroad.

The IRAS return and the ACRA annual return are separate filings. A private company files its annual return within seven months after its financial year end, so a company with a 31 December 2025 year end had until 31 July 2026. Late filing within three months of the deadline costs S$300, and S$600 after that.

From 20 October 2026, under the Corporate and Accounting Laws (Amendment) Act 2025, the annual return eform changes:

• Filers must confirm that the latest particulars held by ACRA are accurate for directors, CEOs, secretaries, auditors and relevant members. That includes names, ID details, nationality, contact address, appointment dates, registered office address and shareholdings.
• There is a new question asking whether any individual performs the role of CEO.
• The rule that a registered office must be open to the public for set hours has been removed, although records must still be made available for inspection on reasonable notice.

For a foreign director, the first point is the one to act on. If you moved from London to Dubai and never updated your address in Bizfile, fix it before your next annual return, not during it.

1. Assuming a loss means no return. If you traded or earned income, you file.
2. Confusing ECI with the annual return. Filing ECI does not satisfy the 30 November deadline.
3. Leaving Corppass to the last week. Foreign ID accounts take time to set up.
4. Thinking the accountant carries the liability. IRAS says directors remain responsible.
5. Using Form C-S when you do not qualify, for example while claiming foreign tax credit.
6. Not updating Bizfile particulars before the next ACRA annual return under the new confirmation rules.

We work with foreign founders who run Singapore companies from outside Singapore. We check which form your company qualifies for, prepare or review the accounts and tax computation with a Singapore accountant, set up Corppass access for non-resident directors, and keep the IRAS and ACRA calendars in one place so nothing lands on the wrong desk. If you are still deciding where to incorporate, our Singapore vs Hong Kong comparison is a good place to start.

If your Singapore company had a financial year ending in 2025, assume a return is due by 30 November 2026 until myTax Portal or IRAS tells you otherwise. Check your form, get Corppass working this week, and file early. The S$5,000 fine is the smaller risk. The bigger one is a director who finds out from a court notice.